Treated refractory material and methods of making

ABSTRACT

A treated refractory material includes a refractory material having a plurality of pores, wherein the refractory material comprises aluminum oxide, silicon oxide, magnesium oxide, chromium oxide, zirconium oxide, titanium oxide, calcium oxide, fireclay, silicon carbide, tungsten, mullite, dolomite, magnesite, magnesium aluminum oxide, chromite, magnetite, or a combination comprising at least one of the foregoing; and a protective material disposed within the plurality of pores of the refractory material, wherein the protective material is selected from the group consisting of aluminum oxide, chromium oxide, silica, rare earth oxides, rare earth zirconates, titanium oxide, mullite, zirconium oxide, zirconium silicate, yttrium oxide, magnesium oxide, iron oxide, and blends thereof.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of and claims benefit to thelegally related application, U.S. Non-provisional patent applicationSer. No. 11/683,260 filed Mar. 7, 2007, which is fully incorporatedherein by reference.

BACKGROUND OF THE INVENTION

In a slagging gasifier, solid feedstocks such as coal or coke arepartially oxidized at about 1300 to 1600 degrees Celsius to produce amixture of carbon monoxide, carbon dioxide, hydrogen, and water (oftenreferred to as a ‘syngas’). The coal can typically contain up to about 5to 25 percent by weight of inorganic minerals that combine to form a lowviscosity molten slag, which contains silicon oxide, aluminum oxide,calcium oxide, and iron oxide.

The walls of the gasifier are lined with refractory material, which iscurrently prepared from chromium oxide (Cr₂O₃) grains or a blend ofCr₂O₃ and aluminum oxide grains, formed into bricks and sintered. Therefractory material has a connected pore structure and is quite porous(e.g. up to 20% porosity by volume). As the slag flows along the wallsof the gasifier, it infiltrates the pores in the refractory material.This infiltration causes refractory degradation through a combination ofgrain dissolution, grain undercutting and macro-cracking.

An improved treated refractory material for reducing the penetration ofliquid slag and an improved method for treating the refractory materialwould be desirable.

BRIEF DESCRIPTION OF THE INVENTION

In one embodiment, a treated refractory material comprises: a refractorymaterial having a plurality of pores, wherein the refractory materialcomprises aluminum oxide, silicon oxide, magnesium oxide, chromiumoxide, zirconium oxide, titanium oxide, calcium oxide, fireclay, siliconcarbide, tungsten, mullite, dolomite, magnesite, magnesium aluminumoxide, chromite, magnetite, or a combination comprising at least one ofthe foregoing; and a protective material disposed within the pluralityof pores of the refractory material, wherein the protective material isselected from the group consisting of aluminum oxide, chromium oxide,silica, rare earth oxides, rare earth zirconates, titanium oxide,mullite, zirconium oxide, zirconium silicate, yttrium oxide, magnesiumoxide, iron oxide, and blends thereof.

In another embodiment, an article includes the treated refractorymaterial and can be a pre-formed structure, a monolith, or a combinationthereof.

In another embodiment, a process for making a treated refractory body,includes adding a protective material to an existing refractory bodycomprising a refractory material, wherein the refractory materialcomprises aluminum oxide, silicon oxide, magnesium oxide, chromiumoxide, zirconium oxide, titanium oxide, calcium oxide, fireclay, siliconcarbide, tungsten, mullite, dolomite, magnesite, magnesium aluminumoxide, chromite, magnetite, or a combination comprising at least one ofthe foregoing, and the protective material is selected from the groupconsisting of aluminum oxide, chromium oxide, silica, rare earth oxides,rare earth zirconates, titanium oxide, mullite, zirconium oxide,zirconium silicate, yttrium oxide, magnesium oxide, iron oxide, andblends thereof.

In still another embodiment, a process for making a refractory materialincludes blending the refractory material with a protective materialand/or a precursor of a protective material, wherein the refractorymaterial comprises aluminum oxide, silicon oxide, magnesium oxide,chromium oxide, zirconium oxide, titanium oxide, calcium oxide,fireclay, silicon carbide, tungsten, mullite, dolomite, magnesite,magnesium aluminum oxide, chromite, magnetite, or a combinationcomprising at least one of the foregoing; and sintering the blend,wherein the precursor material and/or the precursor of the protectivematerial is in elemental or compound form and comprises an element notcomprised in the refractory material selected from the group consistingof silicon, rare earth elements, zirconium, titanium, yttrium,magnesium, iron, and blends thereof.

The various embodiments are relatively inexpensive and provideprotection to refractory materials from the penetration of slag andextend the service life of refractory material.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an XRF Si map of the slag penetration of an untreated brickand treated brick described in Example 1.

FIG. 2 shows an XRF Fe map of the slag penetration of an untreated brickand treated brick described in Example 1.

FIG. 3 shows an XRF Si map of the slag penetration of an untreated brickand treated bricks described in Examples 2-5.

FIG. 4 shows the cross sections of the untreated and treated bricksdescribed in Example 6.

DETAILED DESCRIPTION OF THE INVENTION

Described herein are refractory materials and more particularly, treatedrefractory materials including protective materials configured tominimize slag penetration. In one embodiment, a treated refractory bodycomprises a refractory material having a plurality of pores and aprotective material disposed within the plurality of pores of therefractory material. As used herein, “refractory material” is generallyintended to refer to any suitable material for us in high temperature(e.g., greater than 500 degrees Celsius) systems, such as slagginggasification. Exemplary refractory materials will have chemical andphysical properties that make them stable and able to retain strength asstructures or components of systems that are exposed to the hightemperatures. The refractory materials, therefore, are resistant tothermal shock, chemically stable in the slag and process environment,wear resistant, with high temperature strength, and thermalconductivities and coefficients of thermal expansion suitable for use inthe high temperature systems. The refractory materials are furtherporous and have a connected pore structure, which includes open poresand closed pores. The pores can range in size from about 1 micrometer(μm) to about 200 μm in diameter. In an exemplary embodiment, therefractory material can comprise any type of material suitable for agasifier lining. Exemplary refractory materials include, withoutlimitation, aluminum oxide, silicon oxide, magnesium oxide, chromiumoxide, zirconium oxide, titanium oxide, calcium oxide, fireclay, siliconcarbide, tungsten, mullite, dolomite, magnesite, spinel (magnesiumaluminum oxide), chromite, magnetite, or a combination comprising atleast one of the foregoing.

The refractory material can be formed into a structure (i.e., body)suitable for high temperature systems, such as slagging gasification. Inone embodiment, the refractory body can have a preformed shape. Apreformed refractory body is a refractory material that has been formed(e.g., pre-cast) into a desired shape and sintered. Exemplary refractorypreforms can include, without limitation, bricks, blocks, tiles, and thelike. In another embodiment, the refractory material is a non-preformed,loose material which can be formed into complex shapes, or disposed(e.g., sprayed) into a desired place, and are then sintered before usein the high temperature system. In still another embodiment, therefractory material can be sintered in situ. Some non-preformed,un-fired refractory materials are referred to as “monolithics”.Exemplary monolithics can include, without limitation, castables,moldables, ramming mixes, gunning mixes, mortars, refractory plastics,combinations thereof, and the like. In one embodiment, the refractorybody can form the lining of a slagging gasifier. The lining can beformed from pre-cast bricks, blocks, or tiles, or it can be formed ofrefractory monolithics. In another embodiment, the lining can compriseboth pre-formed and monolithic portions of refractory materials.

The refractory material can be sintered by firing or heat treating thematerial to a temperature of at least about 1000 degrees Celsius (° C.).In one embodiment, the refractory material can be fired at a temperaturefrom about 1000° C. to about 1800° C. The refractory material can befired for a time suitable to sinter the material, and can depend on suchfactors as the material composition, the desired refractory structure,the desired use, and the like. In one embodiment, the refractorymaterial can be fired for at least about 1 hour. In another embodiment,the refractory material can be fired from about 1 hour to about 160hours; specifically about 1 hour to about 5 hours. The refractorymaterial can be sintered in oxidizing, reducing, or neutralenvironments. For example the refractory material can be sintered in airor in a nitrogen or argon environment.

In one embodiment, the refractory material comprises chromium oxide. Inanother embodiment, the refractory material comprises greater than orequal to 40 percent by weight chromium oxide. In another embodiment, therefractory material comprises at least 60 percent by weight chromiumoxide.

In another embodiment, the refractory material comprises chromium oxideand aluminum oxide. The refractory material may comprise from about 40to about 95 percent by weight chromium oxide and from about 5 to about60 percent by weight aluminum oxide, based on the weight of therefractory material. In one embodiment, the refractory materialcomprises from about 60 to about 95 percent by weight chromium oxide andfrom about 5 to about 40 percent by weight aluminum oxide, based on theweight of the refractory material.

In another embodiment, the refractory material comprises chromium oxide,aluminum oxide and zirconium oxide. The refractory material may comprisefrom about 40 to about 90 percent by weight chromium oxide, from about 5to about 10 percent by weight zirconium oxide and from about 5 to about55 percent by weight aluminum oxide, based on the weight of therefractory material. In one embodiment, the refractory materialcomprises from about 60 to about 90 percent by weight chromium oxide,from about 5 to about 10 percent by weight zirconium oxide and fromabout 5 to about 35 percent by weight aluminum oxide, based on theweight of the refractory material.

In still another embodiment, the refractory material comprises chromiumoxide and magnesium oxide. The refractory material may comprise fromabout 40 to about 90 percent by weight chromium oxide, from about 5 toabout 60 percent by weight magnesium oxide and/or from about 5 to about40 percent by weight aluminum oxide, based on the weight of therefractory material. In another embodiment, the refractory material is aspinel based mixture comprising from about 5 to about 70 percent byweight magnesium oxide, and from about 5 to about 70 percent by weightaluminum oxide, based on the weight of the refractory material.

The refractory materials further comprise one or more protectivematerials disposed within the pores of the refractory material.Exemplary protective materials can be selected from the group consistingof aluminum oxide, chromium oxide, silica, rare earth oxides, rare earthzirconates, titanium oxide, mullite, zirconium oxide, zirconiumsilicate, yttrium oxide, magnesium oxide, iron oxide, and blendsthereof.

The protective materials are chemically compatible with the refractorymaterials and will not decompose in typical gasifier operatingatmospheres of up to about 30 to about 60 atm and at typical gasifieroperating temperatures of up to about 1300 to about 1600° C. Exemplaryprotective materials are any type of material that impedes theinfiltration of slag into the refractory material, such as, for example,by decreasing the porosity of the refractory material and producing acomplex reaction between the slag and protective material to lower theslag's effective viscosity. As explained above, liquid slag is a lowviscosity blend of inorganic oxides that is produced as a by-product ina slagging coal gasifier when the coal or coke is partially oxidized.The slag may contain silica, aluminum oxide, calcium oxide and ironoxide. The slag can infiltrate the pores in the refractory material anddegrade the refractory material.

In one embodiment, the protective material comprises material that atleast partially fills the pores in the refractory material to preventthe slag from infiltrating the refractory material and/or material thatreacts with the infiltrating slag to modify the viscosity or wettingbehavior of the slag or to decrease the amount of liquid phase in theslag. In one embodiment, the protective material is selected from thegroup consisting of aluminum oxide, chromium oxide, silica, rare earthoxides, rare earth zirconates, titanium oxide, mullite, zirconium oxide,zirconium silicate, yttrium oxide, magnesium oxide, iron oxide, andblends thereof.

Precursor compounds may be added to the refractory material. Precursorcompounds react or decompose to form a metal oxide, metal silicate ormetal zirconate. In one embodiment, the precursor compound is inelemental or compound form and comprises an element selected from thegroup consisting of silicon, rare earth metals, zirconium, titanium,yttrium, magnesium, iron, and blends thereof. In another embodiment, theprecursor compounds may be salts of metals to transform into metaloxides, metal silicates or metal zirconates. In another embodiment,salts of the metal compounds include nitrates, acetates, hydroxides, orcarbonates. For example, the precursor compounds may be aluminumnitrate, chromium nitrate, silicon nitrate, rare earth nitrates,titanium nitrate, zirconium nitrate, yttrium nitrate, magnesium nitrate,iron nitrate, or blends thereof. In another embodiment, the precursorcompounds may be chromium acetate, silicon acetate, rare earth acetates,zirconium acetate, yttrium acetate, or blends thereof.

Rare earth metals are elements from the lanthanide series, such aslanthanum, cerium, praseodymium, neodymium, promethium, samarium,europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium,ytterbium, lutetium and mixtures thereof. The rare earth oxides areoxides of elements from the lanthanide series, such as lanthanum,cerium, praseodymium, neodymium, promethium, samarium, europium,gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium andlutetium. In one embodiment, the rare earth oxide is cerium oxide. Inanother embodiment, the rare earth oxides may be a mixture or alloy ofrare earth oxides.

Rare earth zirconates are zirconates that have a formula of RE2Zr2O7,where RE is a rare earth element from the lanthanide series, such aslanthanum, cerium, praseodymium, neodymium, promethium, samarium,europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium,ytterbium and lutetium. In one embodiment, the rare earth zirconate iscerium zirconate, gadolinium zirconate, lanthanum zirconate or neodymiumzirconate.

The protective materials may comprise blends. In one embodiment, theprotective material may comprise a blend of aluminum oxide and silica.In another embodiment, the protective material may comprise a blend ofmagnesium oxide and iron oxide. In another embodiment, the protectivematerial may comprise a blend of aluminum oxide, chromium oxide, ironoxide and magnesium oxide. When blends of protective materials areemployed, the compounds may be added to the refractory material togetheror separately.

The amounts of each component in the blend may be in any amount from 0to 100 percent by weight based on the weight of the blend. For example,in one embodiment the blend of aluminum oxide and silica comprises fromabout 10 to about 90 percent by weight of aluminum oxide and from about10 to about 90 percent by weight silica based on the weight of theblend. In another embodiment, the blend of aluminum oxide and silicacomprises from about 20 to about 80 percent by weight of aluminum oxideand from about 20 to about 80 percent by weight silica, based on theweight of the blend. In another embodiment, the blend of aluminum oxideand silica comprises from about 40 to about 60 percent by weight ofaluminum oxide and from about 40 to about 60 percent by weight silica,based on the weight of the blend.

The magnesium oxide and iron oxide combination comprises from about 10to about 90 percent by weight magnesium oxide and from about 10 to about90 percent by weight iron oxide, based on the weight of the combination.In another embodiment, the magnesium oxide and iron oxide combinationcomprises from about 30 to about 70 percent by weight magnesium oxideand from about 30 to about 70 percent by weight iron oxide, based on theweight of the combination. In another embodiment, the magnesium oxideand iron oxide combination comprises from about 40 to about 60 percentby weight magnesium oxide and from about 40 to about 60 percent byweight iron oxide, based on the weight of the combination.

In one embodiment, the blend of aluminum oxide, chromium oxide, ironoxide and magnesium oxide comprises from about 1 to about 50 percent byweight aluminum oxide, from about 1 to about 50 percent by weightchromium oxide, from about 1 to about 50 percent by weight iron oxideand from about 1 to about 50 percent by weight magnesium oxide, based onthe weight of the blend.

The protective material may be added to the pores of the porousrefractory material by infiltrating the protective material into therefractory material and dispersing the material into the pores. Theprotective material infiltrates the refractory material by any methodknown in the art, such as painting, spraying, dipping, coating or vacuuminfiltration. In one embodiment, the protective material infiltrates therefractory material as a suspension, slurry or liquid solution. Theprotective material may be a precursor compound, such as a salt, and isdispersed in a solvent, such as water, an alcohol or other type ofsolvent. In one embodiment, the precursor material may be a nitrate oracetate salt. In another embodiment, the precursor may be a rare earthmetal and dissolved in acid to form a solution. The suspension, slurry,liquid solution, or molten salt penetrates into the refractory materialdepositing the protective material throughout the pores of the porousrefractory material. The refractory material is heat treated toevaporate or decompose the solvent and transform the precursor into theprotective material leaving the protective material situated throughoutthe open pores of the refractory material. For example, chromium nitrateor aluminum nitrate is infiltrated into the refractory material and heattreated to leave chromium oxide or aluminum oxide situated in the poresof the refractory material. The heat treatment to evaporate or decomposethe solvent and transform the precursor into the protective material isat a temperature in a range of from about 100° C. to about 1500° C. fromabout 1 hour to about 10 hours. In another embodiment, the heattreatment is at a temperature in a range of from about 300° C. to about500° C. from about 1 to about 5 hours.

The protective material may infiltrate the refractory material in theform of a powder. The powder may comprise micron-sized or nano-sizedparticles. In one embodiment, the particle sizes range from about 5nanometers (nm) to about 200 μm. In another embodiment, the particlesizes range from about 5 nm to about 100 μm. In another embodiment, thepowder comprises particles ranging in size from about 1 μm to about 10μm. In another embodiment, the particle sizes range from about 1 μm toabout 2 μm. In one embodiment, the protective material comprisesnano-sized particles. In one embodiment, the protective materialcomprises particle sizes from about 5 nm to about 100 nm. In anotherembodiment, the protective material comprises a particle size from about5 nm to about 10 nm. Nano-sized powders are infiltrated as colloidsolutions with typical solid loadings of about 10 to about 50 percent byweight. The colloid solution may be an aqueous suspension and maycontain surfactants to aid in dispersing the particles.

In another embodiment, the protective material is dispersed by vacuuminfiltration. For example, an existing preformed refractory body, suchas a sintered brick or an as-fabricated brick, can be placed undervacuum. A solution or suspension of the protective material is admittedto penetrate the pores of the refractory material of the refractory bodyand the vacuum is released. In an alternative embodiment, the refractorybody can first be immersed in the suspension or solution and a vacuumapplied. The solution or suspension infiltrates the refractory materialas the vacuum is applied. Air pressure may assist to produce furtherinfiltration. In a further embodiment, the solution or suspension isadmitted into the material by infiltration at atmospheric pressure.

In one embodiment, the amount of protective material comprises fromabout 2 to about 20 percent by volume based on the total volume of therefractory material. The protective material infiltrates the refractorymaterial to partially fill the pores of the refractory material. In oneembodiment, the protective material fills from about 3 percent to about60 percent of the pore volume. In another embodiment, the protectivematerial infiltrates the refractive material to fill from about 20percent to about 50 percent of the pore volume. In one embodiment, theprotective material at least partially coats the inner surfaces of thepores and forms a sacrificial barrier within the pores to inhibit thepenetration of liquid slag into the refractory material.

The refractory material may be treated with the protective materialbefore or after the refractory material has been assembled into agasifier. In one embodiment, the protective material is applied as afinal coating to the refractory material lining the walls of thegasifier. The treated refractory brick retains the mechanical andphysical properties of the as-fabricated brick.

The treated refractory material minimizes the penetration of liquid slaginto the refractory material. In one embodiment, as the slag begins topenetrate the surface pores of the refractory material, the liquid slagencounters the protective materials disposed within the pores. Theliquid slag reacts with the protective materials to create either ahigh-melting phase or phases or a high-viscosity liquid. In either case,further penetration of the liquid slag is suppressed. Creation of ahigh-melting phase or phases reduces the volume of liquid phase andminimizes slag penetration into the refractory material. Increasing theviscosity also inhibits penetration of the liquid slag deeper into therefractory material. For example, in one embodiment, aluminum oxide isdisposed within pores of the refractory material. When the infiltratingslag contacts the aluminum oxide, the slag/oxide reaction precipitateshigher-melting phases, such as anorthite, and reduces the volume ofliquid phase available for penetration into the refractory material.

In another embodiment, when fine particles of silica are disposed withinpores of the refractory material, the slag will become enriched insilica. The addition of silica increases the viscosity of the liquidslag. Such an increased viscosity inhibits slag penetration into therefractory material.

A combination of approaches can be used to both increase the viscosityand raise the melting temperature of the liquid slag. In one embodiment,the protective infiltrant is a blend of aluminum oxide and silica. Thealuminum oxide causes precipitation of higher-melting phases and thesilica increases the viscosity of the remaining liquid slag.

In another embodiment, the protective material minimizes the penetrationof the slag into the refractory material by filling openings betweengrains of the refractory material. For example, chromium oxide isresistant to dissolution in slag, but reduces the permeability of therefractory material by filling channels between grains with relativelyinert material.

In another embodiment, a process for making a treated refractory bodycomprises adding one or more protective materials to an existingrefractory body, wherein the protective materials enter the pores ofporous sintered refractory material of the refractory body, wherein theprotective material is selected from the group consisting of aluminumoxide, chromium oxide, silica, rare earth oxides, rare earth zirconates,titanium oxide, mullite, zirconium oxide, zirconium silicate, yttriumoxide, magnesium oxide, iron oxide, and blends thereof.

As explained above, the protective material is added to the refractorymaterial by infiltrating the protective material into the refractorymaterial and dispersing the material into the pores. The protectivematerial infiltrates the refractory material by any method known in theart, such as painting, spraying, dipping, coating or vacuuminfiltration. The protective material may be a precursor compound, suchas a salt, and is dispersed in a solvent, such as water, an alcohol orother type of solvent. In one embodiment, the precursor material may bea nitrate or acetate salt. In another embodiment, the precursor materialmay be a metal, dissolved in acid to form a solution.

In another embodiment, a process for making treated refractory materialcomprises blending refractory material and one or more protectivematerials and sintering the blend, wherein the protective material isselected from the group consisting of silica, rare earth oxides, rareearth zirconates, titanium oxide, mullite, zirconium silicate, yttriumoxide, magnesium oxide, iron oxide, and blends thereof.

In another embodiment, a process for making treated refractory materialcomprises blending the refractory material and a protective materialand/or a precursor of a protective material and sintering the blend,wherein the protective material and/or the precursor material is inelemental or compound form and comprises an element selected from thegroup consisting of silicon, rare earth elements, zirconium, titanium,yttrium, magnesium, iron, and blends thereof.

As explained above, precursor compounds react or decompose to form ametal oxide, metal silicate or metal zirconate. In one embodiment, theprecursor compounds may be salts that can be transformed into the metaloxides, metal silicates or metal zirconates upon heat treatment. Inanother embodiment, salts of the metal compounds include nitrates andacetates.

The protective material is blended with the refractory material in anyamount that is suitable for treating the refractory material. In oneembodiment, the protective material is added in amount of from about 1to about 10 percent by weight based on the weight of the blend. Inanother embodiment, the protective material is added in amount of fromabout 5 to about 10 percent by weight based on the weight of the blend.

The blend of refractory material and protective material may be formedinto any desired shape. In one embodiment, the refractory material isformed into a pre-cast shape, such as a brick, block, tile, or the like.In another embodiment, the refractory material is a monolithic. In stillanother embodiment, the refractory material has both pre-formed andmonolithic portions. The blend of refractory material and protectivematerial is sintered by firing or heat treating the material to atemperature of at least about 1000° C. In one embodiment, the materialis fired at a temperature from about 1000° C. to about 1800° C. In oneembodiment, the refractory material is fired for at least about 1 hour.In another embodiment, the refractory material is fired from about 1hour to about 24 hours. The refractory material may be sintered in airor in a nitrogen or argon environment.

The treated refractory materials can impart some measure ofself-healing. If the surface layers of the refractory material areremoved, the underlying protective material disposed within therefractory material will again react with the slag to reform a renewedprotective layer against further infiltration of slag.

In order that those skilled in the art will be better able to practicethe present disclosure, the following examples are given by way ofillustration and not by way of limitation.

EXAMPLES Example 1

A sintered high chromia (90 wt %) brick was infiltrated with chromium(III) nitrate solution multiple times followed by subsequent heattreatments in air at 600° C. for 2 hours to decompose the nitrate saltinto chromium oxide. The weight of the protective material constitutedapproximately 10 percent by weight of the refractory brick after allinfiltrations. The infiltrated brick was then annealed in nitrogen at1600° C. for 20 hours to pre-react the chromium oxide before the slaginfiltration. The porosity of the untreated refractory before the slaginfiltration was about 18-20 vol. %. After infiltration and heattreatment, the porosity was about 12-14 vol. %.

A slag infiltration test via isothermal annealing of cups filled withslag was performed on the brick infiltrated with chromium oxide and onan untreated brick. The slag composition contained 59.0% silica, 10.7%aluminum oxide, 8.3% calcium oxide, 21.6% iron oxide and 0.3% potassiumoxide. Test parameters were 1490° C. for 20 hours at an oxygen partialpressure of 10̂-10 atm provided via a mixture of wet and dry N2/3% H2gas.

Subsequent analysis of slag penetration by XRF mapping of Si and Fedistribution at the brick cross-section revealed that slag penetrationin the treated brick is much less than the slag penetration into theuntreated brick. FIG. 1 shows an XRF mapping of Si of the slagpenetration of the untreated sintered brick and the treated brick. FIG.2 shows an XRF mapping of Fe of the slag penetration of the untreatedbrick and the treated brick.

Example 2

Example 1 was reproduced with the exception of using chromium (III)acetate (Cr3(OH)3(CH3COO)2 as the precursor to the chromium oxideprotective material. A slag infiltration test via isothermal annealingof cups filled with slag was performed on the brick infiltrated withchromium oxide and on an untreated brick. Test parameters were 1500° C.for 20 hours at an oxygen partial pressure of 10̂-10 atm provided via amixture of wet and dry N2/3% H2 gas.

Subsequent analysis of slag penetration by XRF mapping of Sidistribution at the brick cross-section revealed that slag penetrationin the treated brick is much less than the slag penetration in theuntreated brick. FIG. 3A shows an XRF mapping of Si of the slagpenetration of the untreated brick and the brick treated with chromiumoxide.

Example 3

Example 1 was reproduced with the exception of using aluminum nitrate asthe precursor for the aluminum oxide protective material. A slaginfiltration test via isothermal annealing of cups filled with slag wasperformed on the brick infiltrated with aluminum oxide and on anuntreated brick. Test parameters were 1500° C. for 20 hours at an oxygenpartial pressure of 10̂-10 atm provided via a mixture of wet and dryN2/3% H2 gas.

Subsequent analysis of slag penetration by XRF mapping of Sidistribution at the brick cross-section revealed that slag penetrationin the treated brick is much less than the slag penetration in theuntreated baseline brick. FIG. 3B shows an XRF mapping of Si of the slagpenetration of the untreated brick and the brick treated with aluminumoxide.

Example 4

Example 1 was reproduced with the exception of using cerium nitrate asthe precursor for the cerium oxide protective material. A slaginfiltration test via isothermal annealing of cups filled with slag wasperformed on the brick infiltrated with cerium oxide and on an untreatedbaseline brick. Test parameters were 1500° C. for 20 hours at an oxygenpartial pressure of 10̂-10 atm provided via a mixture of wet and dryN2/3% H2 gas.

Subsequent analysis of slag penetration by XRF mapping of Sidistribution at the brick cross-section revealed that slag penetrationin the treated brick is much less than the slag penetration in theuntreated brick. FIG. 3C shows an XRF mapping of Si of the slagpenetration of the untreated brick and the brick treated with ceriumoxide.

Example 5

Example 1 was reproduced with the exception of using gadolinium nitrateand zirconium nitrate as the precursors for the gadolinium zirconateprotective material. A slag infiltration test via isothermal annealingcups filled with slag was performed on the brick infiltrated withgadolinium zirconium oxide and on an untreated baseline brick. Testparameters were 1500° C. for 20 hours at an oxygen partial pressure of10̂-10 atm provided via a mixture of wet and dry N2/3% H2 gas.

Subsequent analysis of slag penetration by XRF mapping of Sidistribution at the brick cross-section revealed that slag penetrationin the treated brick is much less than the slag penetration in theuntreated baseline brick. FIG. 3D shows an XRF mapping of Si of the slagpenetration of the untreated brick and the brick treated with gadoliniumzirconate.

Example 6

A fused-cast and sintered brick of 75% weight chromia was vacuuminfiltrated multiple times with a colloidal suspension of nano-scaleparticles of Al2O3 having particle sizes of about 50 nm. After eachinfiltration, the brick was heated to 800° C. for 4 hours in air todecompose the dispersant. The same refractory brick was subsequentlyvacuum infiltrated multiple times with a colloidal suspension ofnano-scale particles of SiO2 having particle sizes of about 12 nm.Between each of the SiO2 infiltrations the brick was heated to 120° C.for 2 hours to remove water.

A slag infiltration test via isothermal annealing of cups filled withslag was performed on the brick infiltrated with aluminum oxide andsilica. The slag infiltration test was also performed on an untreatedbrick. Test parameters were 1500° C. for 20 hours at an oxygen partialpressure of 10̂-10 atm provided via a mixture of wet and dry N2/3% H2gas.

The treated brick clearly shows reduced slag infiltration from 15 mm to3 mm slag-penetration when compared with the untreated brick at thebrick cross-section. The cross sections of the untreated brick and thetreated brick at an oxygen partial pressure of 10̂-10 atm provided via amixture of wet and dry N2/3% H2 gas are shown in FIG. 4. The treatedbrick clearly shows reduced slag infiltration from 15 mm to 3 mm 15 slagpenetration when compared with the untreated brick at the brickcross-section. The cross sections of the untreated brick and the treatedbrick are shown in FIG. 4.

As used herein, the oxidation state of the elements used can vary. Themention of the oxide of any element in one oxidation state includesoxides of this element in all existing oxidation states. For instance,cerium oxide includes Ce₂O₃ and CeO₂, iron oxide includes FeO and Fe₂O₃and chromium oxide includes Cr₂O₃ and CrO.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention.Ranges disclosed herein are inclusive and combinable (e.g., ranges of“up to about 25 wt %, or, more specifically, about 5 wt % to about 20 wt%”, is inclusive of the endpoints and all intermediate values of theranges of “about 5 wt % to about 25 wt %,” etc.). “Combination” isinclusive of blends, mixtures, alloys, reaction products, and the like.Furthermore, the terms “first,” “second,” and the like, herein do notdenote any order, quantity, or importance, but rather are used todistinguish one element from another, and the terms “a” and “an” hereindo not denote a limitation of quantity, but rather denote the presenceof at least one of the referenced item. The modifier “about” used inconnection with a quantity is inclusive of the stated value and has themeaning dictated by context, (e.g., includes the degree of errorassociated with measurement of the particular quantity). The suffix“(s)” as used herein is intended to include both the singular and theplural of the term that it modifies, thereby including one or more ofthat term (e.g., the colorant(s) includes one or more colorants).Reference throughout the specification to “one embodiment”, “anotherembodiment”, “an embodiment”, and so forth, means that a particularelement (e.g., feature, structure, and/or characteristic) described inconnection with the embodiment is included in at least one embodimentdescribed herein, and may or may not be present in other embodiments. Inaddition, it is to be understood that the described elements may becombined in any suitable manner in the various embodiments.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which the embodiments of the inventionbelong. It will be further understood that terms, such as those definedin commonly used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of the relevant artand the present disclosure, and will not be interpreted in an idealizedor overly formal sense unless expressly so defined herein.

While the disclosure has been described with reference to an exemplaryembodiment, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the disclosure. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the disclosure without departing fromthe essential scope thereof. Therefore, it is intended that thedisclosure not be limited to the particular embodiment disclosed as thebest mode contemplated for carrying out this disclosure, but that thedisclosure will include all embodiments falling within the scope of theappended claims.

1. A treated refractory material, comprising: a refractory materialhaving a plurality of pores, wherein the refractory material comprisesaluminum oxide, silicon oxide, magnesium oxide, chromium oxide,zirconium oxide, titanium oxide, calcium oxide, fireclay, siliconcarbide, tungsten, mullite, dolomite, magnesite, magnesium aluminumoxide, chromite, magnetite, or a combination comprising at least one ofthe foregoing; and a protective material disposed within the pluralityof pores of the refractory material, wherein the protective material isselected from the group consisting of aluminum oxide, chromium oxide,silica, rare earth oxides, rare earth zirconates, titanium oxide,mullite, zirconium oxide, zirconium silicate, yttrium oxide, magnesiumoxide, iron oxide, and blends thereof.
 2. The treated refractorymaterial of claim 1, wherein the rare earth oxides comprise oxides ofrare earth elements selected from the group consisting of lanthanum,cerium, praseodymium, neodymium, promethium, samarium, europium,gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium andlutetium.
 3. The treated refractory material of claim 1, wherein therare earth zirconate has a formula of RE₂Zr₂O₇, where RE is a rare earthelement selected from the group consisting of lanthanum, cerium,praseodymium, neodymium, promethium, samarium, europium, gadolinium,terbium, dysprosium, holmium, erbium and ytterbium.
 4. The treatedrefractory material of claim 1, wherein the protective material fillsfrom about 3 to about 60 percent of the volume of the plurality of poresin the refractory material.
 5. The treated refractory material of claim1, wherein the protective material is a powder.
 6. The treatedrefractory material of claim 5, wherein the protective material has aparticle size in the range of from about 5 nm to about 200 μm.
 7. Thetreated refractory material of claim 1, wherein an amount of theprotective material comprises from about 2 to about 20 percent by volumebased on the total volume of the refractory material.
 8. An articlecomprising the treated refractory material of claim
 1. 9. The article ofclaim 8, wherein the article comprises a pre-formed structure.
 10. Thearticle of claim 9, wherein the pre-formed structure comprises a brick,block, tile, or a combination comprising at least one of the foregoing.11. The article of claim 8, wherein the article comprises a monolithic.12. The article of claim 11, wherein the monolith comprises a castable,moldable, ramming mix, gunning mix, mortar, refractory plastic, orcombination comprising at least one of the foregoing.
 13. The article ofclaim 1, wherein the article comprises a combination of a pre-formedstructure and a monolithic portion.
 14. A process for making a treatedrefractory body, comprising: adding a protective material to an existingrefractory body comprising a refractory material, wherein the refractorymaterial comprises aluminum oxide, silicon oxide, magnesium oxide,chromium oxide, zirconium oxide, titanium oxide, calcium oxide,fireclay, silicon carbide, tungsten, mullite, dolomite, magnesite,magnesium aluminum oxide, chromite, magnetite, or a combinationcomprising at least one of the foregoing, and the protective material isselected from the group consisting of aluminum oxide, chromium oxide,silica, rare earth oxides, rare earth zirconates, titanium oxide,mullite, zirconium oxide, zirconium silicate, yttrium oxide, magnesiumoxide, iron oxide, and blends thereof.
 15. The process of claim 14,further comprising forming the existing refractory body and sinteringthe existing refractory body, wherein the body comprises a brick, block,tile, or a combination comprising at least one of the foregoing.
 16. Theprocess of claim 14, wherein the rare earth oxides comprise oxides ofrare earth elements selected from the group consisting of lanthanum,cerium, praseodymium, neodymium, promethium, samarium, europium,gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium andlutetium.
 17. The process of claim 14, wherein the rare earth zirconatehas a formula of RE₂Zr₂O₇, where RE is a rare earth element selectedfrom the group consisting of lanthanum, cerium, praseodymium, neodymium,promethium, samarium, europium, gadolinium, terbium, dysprosium,holmium, erbium and ytterbium.
 18. The process of claim 14, wherein theprotective material is added to a plurality of pores in the refractorymaterial by painting, spraying, dipping, coating or vacuum infiltration.19. The process of claim 14, further comprising sintering the treatedrefractory body, wherein the refractory material and the protectivematerial do not comprise the same compounds.
 20. The process of claim18, further comprising forming a slurry comprising the protectivematerial before adding the protective material to the refractorymaterial.
 21. The process of claim 14, wherein the protective materialis added to the refractory material after the refractory material hasbeen disposed in a gasifier.
 22. A process for making a treatedrefractory material comprising: blending a refractory material with aprotective material and/or a precursor of a protective material, whereinthe refractory material comprises aluminum oxide, silicon oxide,magnesium oxide, chromium oxide, zirconium oxide, titanium oxide,calcium oxide, fireclay, silicon carbide, tungsten, mullite, dolomite,magnesite, magnesium aluminum oxide, chromite, magnetite, or acombination comprising at least one of the foregoing, and sintering theblend, wherein the protective material and/or the precursor of theprotective material is in elemental or compound form and comprises anelement not comprised in the refractory material selected from the groupconsisting of silicon, rare earth elements, zirconium, titanium,yttrium, magnesium, iron, and blends thereof.
 23. The process of claim22, wherein the protective material is added in an amount of from about1 to about 10 percent by weight based on the weight of the blend. 24.The process of claim 22, further comprising forming the blend into aselected one or both of a pre-formed structure and a monolith andsintering the blend at a temperature from about 1000° C. to about 1800°C. for about 1 to about 160 hours.